A stationary cooling station for cooling wafers after the wafers have been subjected to semiconductor processing supports the wafer by flowing gas in accordance with the Bernoulli principle. An upper wall of the cooling station contains a plurality of gas outlets that direct gas to flow over the top surface of the wafer. In this way, a low-pressure region is created over the wafer and the wafer is suspended within the cooling station, without directly contacting any surface for support. In addition to providing lift for the wafer, the gas is a thermally conductive gas that can cool the wafer by conducting heat away from it.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A semiconductor substrate-holding station for holding a semiconductor substrate, comprising: a ceiling and a floor defining a substrate space therebetween for accommodating a substrate; a stationary gas outlet assembly mounted in fixed position relative to the ceiling and floor and configured to suspend the substrate in accordance with Bernoulli's principle, the gas outlet assembly having a plate, the plate comprising: a first axis extending forwardly and rearwardly along a horizontal surface of the plate; a first plurality of outlets on one side of the first axis for exhausting gas received by the assembly into the substrate space and for establishing a plurality of streams of gas flow toward a perimeter of the substrate upon retention of the substrate; a second plurality of outlets on another side of the first axis for exhausting the gas received by the assembly into the substrate space and for establishing a plurality of streams of gas flow toward the perimeter of the substrate upon retention of the substrate; and a central outlet disposed generally coincident with the first axis for exhausting the gas received by the assembly and for establishing a flow of gas intermediate the plurality of streams of gas flow emanating from the first and second plurality of outlets upon retention of the substrate, wherein outlets are configured to exhaust the gas at an angle and direction to create a low pressure zone adjacent the substrate.
2. The semiconductor substrate-holding station of claim 1 , wherein the horizontal surface faces downwards.
3. The semiconductor substrate-holding station of claim 2 , further comprising a showerhead for exhausting gas upwards into the substrate space, the showerhead located opposite the plate.
4. The semiconductor substrate-holding station of claim 1 , wherein the first plurality of outlets numbers at least three.
5. The semiconductor substrate-holding station of claim 4 , wherein the second plurality of outlets numbers at least three.
6. The semiconductor substrate-holding station of claim 5 , further comprising a rear central outlet in the plate, the rear central outlet disposed generally coincident with the first axis and rearwardly of the central outlet.
7. The semiconductor substrate-holding station of claim 1 , wherein a diameter of each of the outlets is between about 0.018 and about 0.020 inch.
8. The semiconductor substrate-holding station of claim 1 , wherein an angle of orientation, with respect to the horizontal surface, of each outlet of the first and the second plurality of outlets through the plate is substantially similar.
9. The semiconductor substrate-holding station of claim 8 , wherein the outlets are angled between about 29° and about 31° with respect to the horizontal surface.
10. The semiconductor substrate-holding station of claim 9 , wherein a majority of the outlets point rearwardly.
11. The semiconductor substrate-holding station of claim 10 , further comprising one or more substrate obstructions positioned rearwardly of the plate, the obstructions configured to contact an edge of the substrate and to maintain the substrate positioned under the gas outlet assembly, upon retention of the substrate.
12. A semiconductor substrate holding station, comprising: an upper horizontal surface and a lower horizontal surface defining a wafer space configured to accommodate a semiconductor wafer; and an immobile gas discharge assembly, the gas discharge assembly having a plurality of gas outlets configured to exhaust a gas onto a face of the wafer, wherein the gas discharge assembly is configured to suspend the wafer by the Bernoulli principle utilizing the plurality of gas outlets, with both faces of the wafer vertically separated from the upper and the lower horizontal surfaces.
13. The holding station of claim 12 , wherein the gas outlets are in gas communication with an inert gas source.
14. The holding station of claim 13 , wherein the inert gas source contains nitrogen gas.
15. The holding station of claim 13 , wherein the inert gas source contains a highly thermally conductive gas.
16. The holding station of claim 15 , wherein the thermally conductive gas comprises helium.
17. The holding station of claim 15 , wherein the thermally conductive gas comprises argon.
18. The holding station of claim 12 , wherein the cooling assembly provides gas flow through the upper horizontal surface to the wafer space.
19. The holding station of claim 18 , further comprising a showerhead to provide gas flow through the lower horizontal surface to the wafer space.
20. The holding station of claim 19 , wherein the cooling assembly provides gas flow through the lower horizontal surface to the wafer space.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
February 15, 2005
December 12, 2006
Browse 5M+ US patents with plain-English claim translations and AI-generated analysis.